1. Field of the Invention
The present invention generally relates to a hollow aluminum bat including a tubular handle portion at one end thereof merging into a tubular barrel at the other with the barrel having a constant external and internal diameter and a closure end cap. The improvement constituting the present invention is the provision of grooves formed in the internal surface of the barrel which reduces the weight of the barrel to enable the barrel to be made with a larger constant diameter throughout its length with the grooves maintaining the rigidity, resistance to deformation, the trampoline effect and all impact characteristics of the barrel with a ball. The grooves may include a continuous spiral groove having a plurality of closely associated convolutions, a plurality of longitudinally spaced, circumferential grooves, or a plurality of circumferentially spaced longitudinal grooves formed in the interior surface of the constant diameter barrel and oriented over substantially the full length of the accepted hitting zone defined by the barrel.
2. Description of the Prior Art
Hollow aluminum bats including a hollow handle portion and a hollow barrel with an end cap have been well known for many years and are being used by many ball players. The following prior art relates to this field of endeavor.
U.S. Pat. Nos. PA1 3,727,295 PA1 3,779,551 PA1 3,811,596 PA1 3,861,682 PA1 3,963,239 PA1 Canadian Patent PA1 962291
As discussed in the above-mentioned co-pending application, hollow aluminum bats previously marketed utilized a maximum barrel diameter of 23/4 inches but the end portion of the barrel tapered downwardly to 25/8 inch in order to accept a 25/8 inch end cap and also to provide sufficient physical characteristics to the barrel to maintain the impact characteristics with a ball. The above-mentioned co-pending application included a specific end cap and groove in the interior of the end portion of the barrel which cooperated in a manner to enable the barrel to have a constant external diameter up to 23/4 inches throughout its length and still maintain the desired impact characteristics with a ball.
None of the prior art discloses the concept of providing internal grooves in the interior surface of the barrel substantially throughout the length of the barrel to reduce the overall weight of the bat even though the barrel has a constant external diameter up to and including 23/4 inches throughout its length thus enabling the acceptable hitting zone to be extended with the grooves enabling the weight of the bat to be reduced while maintaining the impact characteristics and structural integrity of the barrel.